Synergistic herbicidal compositions comprising herbicides from the benzoylcyclohexanedione group for use in rice crops

ABSTRACT

Described are herbicidal compositions comprising 
     A) at least one compound from the benzoylcyclohexanedione group and 
     B) at least one compound from the group of the herbicides which act selectively against monocotyledonous and/or dicotyledonous harmful plants in rice. 
     These compositions have a superior action compared with the herbicides employed individually.

The invention relates to the technical field of the crop protectionproducts which can be employed against undesired vegetation and whichcomprise, as active ingredients, a combination of at least twoherbicides.

More specifically, it relates to herbicidal compositions for use in ricewhich comprise, as active ingredient, a herbicide from thebenzoylcyclohexanedione group in combination with at least one furtherherbicide.

Herbicides from the abovementioned benzoylcyclohexanedione group areknown from a large number of documents. Thus, for example, theherbicidal action of a large number of such compounds is described in WO98/29406, WO 00/21924 and WO 01/07422. Some of thebenzoylcyclohexanediones mentioned in WO 00/21924 have a good herbicidalaction against harmful plants which grow in rice crops.

In practice, however, the use of the benzoylcyclohexanediones known fromthese publications frequently entails disadvantages. Thus, theherbicidal activity is not always sufficient, or, if the herbicidalactivity is sufficient, undesired damage to the rice plants is observed.

The activity of herbicides depends, inter alia, on the type of theherbicide employed, its application rate, the preparation, the harmfulplants to be controlled, the climatic conditions and soil conditions andthe like. Another criterion is the duration of action or degradationrate of the herbicide. Where appropriate, changes in the sensitivity ofharmful plants to an active ingredient, which may occur upon prolongeduse or within a geographically defined area, may also have to be takeninto account. Such changes manifest themselves as more or lesspronounced losses of action and can only be compensated for to a certainextent by increasing the application rates of the herbicides.

Owing to the large number of possible influencing factors, there existsvirtually no single active ingredient which combines the desiredproperties for the various uses, in particular with regard to thespecies of the harmful plants and the climatic zones. What is more,there are constant demands for achieving the effect with increasinglysmaller herbicide rates. A lesser rate reduces not only the amount of anactive ingredient required for application, but also, as a rule, theamount of formulation auxiliaries required. Both reduce the financialinput and improve the eco-friendliness of the herbicide treatment.

A method which is frequently used for improving the use characteristicsof a herbicide is to combine the active ingredient with one or moreother active ingredients which contribute the desired additionalproperties. However, phenomena of physical and biologicalincompatibility are frequently observed when several active ingredientsare used as a combination, for example lack of stability of acoformulation, degradation of an active ingredient, or antagonism of theactive ingredients. In contrast, combinations of active ingredients withan advantageous spectrum of action, high stability and the highestpossible synergistically enhanced action, which allows the applicationrate to be reduced in comparison with the individual application of theactive ingredients to be combined, are desired.

Herbicidal mixtures of2-(4-methylsulfonyl-2-nitrobenzoyl)-1,3-cyclohexanedione with asulfonylurea from the group consisting of nicosulfuron, rimsulfuron,thifensulfuron-methyl, primisulfuron-methyl, prosulfuron andhalosulfuron are disclosed in WO 97/48275. However, these mixtures arenot suitable for use in rice crops since they also inflict considerabledamage on the rice plants.

It is an object of the present invention to provide herbicidalcompositions for use in rice crops, which compositions have improvedproperties compared with the prior art.

The invention relates to herbicidal compositions comprising an effectivecontent of

A) at least one compound of the formula (I) and agriculturally customarysalts thereof [component (A)]

 where

R¹ is C₁-C₄-alkyl;

R² is OR⁶, SO_(m)R⁷, cyanato, cyano, thiocyanato or halogen;

R³ and R⁴ independently of one another are hydrogen, halogen,C₁-C₄-alkyl, halogen-C₁-C₄-alkyl, cyano, nitro or SO_(m)R⁷;

R⁵ is O—(CH₂)_(a)—O—(CH₂)_(b)—OR⁷, C₃-C₈-cycloalkyloxy,C₃-C₈-cycloalkyl-C₁-C₄-alkyloxy, 2-tetrahydrofuranylmethoxy,3-tetrahydrofuranyl-methoxy, 2-tetrahydro-2H-pyranylmethoxy,2-tetrahydrothienylmethoxy, 2-furanylmethoxy or 2-thienylmethoxy;

R⁶ is hydrogen, C₁-C₄-alkyl or halogen-C₁-C₄-alkyl;

R⁷ is C₁-C₄-alkyl, C₂-C₄-alkenyl, C₂-C₄-alkynyl, halogen-C₁-C₄-alkyl,halogen-C₂-C₄-alkenyl or halogen-C₂-C₄-alkynyl;

n is 0, 1, 2, 3, 4, 5 or 6;

m is 0, 1 or 2;

a is 2, 3 or 4;

b is 2,3 or 4;

and

B) at least one compound [component (B)] from the group consisting ofthe herbicides 2,4-D (B1.1), benzobicyclon (B2.1), benzofenap (B3.1),bifenox (B4.1), cafenstrole (B5.1), chlorimuron-ethyl (B6.1),cinmethylin (B7.1), daimuron (B5.2), dimethametryn (B8.1), dithiopyr(B5.3), etobenzamide (B9.1), fentrazamide (B5.4), indanofan (B10.1),MCPA (B1.2), oxadiazon (B4.2), piperophos (B5.5), pyrazosulfuron-ethyl(B6.2), pyributicarb (B11.1), pyriftalide (=NOJ-100) (B12.1),pyriminobac-methyl (B6.3), profoxydim (B13.1) and quinoclamine (B14.1),

these compositions comprising the compounds of the formula (I) or saltsthereof [component (A)] and the compounds of the group B) [component(B)] in a weight ratio of 1:200 to 200:1.

Preferred compositions comprise the compounds of the formula (I) orsalts thereof [component (A)] and the compounds of group B) [component(B)] in a weight ratio of 1:20 to 20:1.

In formula (I) and all the subsequent formulae, chain-likecarbon-containing radicals such as alkyl, alkoxy, haloalkyl, haloalkoxy,alkylamino and alkylthio and the corresponding unsaturated radicalsand/or radicals which are substituted in the carbon skeleton, such asalkenyl and alkynyl, can in each case be straight-chain or branched.Alkyl radicals, also in the composite meanings such as alkoxy, haloalkyland the like, are, for example, methyl, ethyl, n- or i-propyl, n-, i-,t- or 2-butyl. Alkenyl and alkynyl radicals have the meanings of thepossible unsaturated radicals which correspond to the alkyl radicals;alkenyl is, for example, allyl, 1-methylprop-2-en-1-yl,2-methylprop-2-en-1-yl, but-2-en-1-yl, but-3-en-1-yl,1-methylbut-3-en-1-yl and 1-methylbut-2-en-1-yl; alkynyl is, forexample, propargyl, but-2-in-1-yl, but-3-in-1-yl, 1-methylbut-3-in-1-yl.The multiple bond can be located in any desired position of theunsaturated radical.

Cycloalkyl is a carbocyclic saturated ring system, for examplecyclopropyl, cyclopentyl or cyclohexyl.

Halogen is fluorine, chlorine, bromine or iodine. Haloalkyl andhaloalkenyl are alkyl, alkenyl or alkynyl, each of which is partially orfully substituted by halogen, preferably by fluorine, chlorine and/orbromine, in particular by fluorine and/or chlorine, for example CF₃,CHF₂, CH₂F, CF₃CF₂, CH₂FCHCl, CCl₃, CHCl₂, CH₂CH₂Cl; haloalkoxy is, forexample, OCF₃, OCHF₂, OCH₂F, CF₃CF₂O, OCH₂CF₃ and OCH₂CH₂Cl; this alsoapplies analogously to haloalkenyl.

Depending on the type and the linkage of the substituents, the compoundsof the formula I may exist as stereoisomers. If, for example, one ormore alkenyl groups are present, diastereomers may occur. If, forexample, one or more asymmetric carbon atoms are present, enantiomersand diastereomers may occur. Stereoisomers can be obtained from themixtures obtained in the preparation by customary separation methods,for example by chromatographic separation methods. Equally,stereoisomers may be prepared selectively by using stereoselectivereactions and optically active starting materials and/or auxiliaries.The invention also relates to all stereoisomers and their mixtures whichare encompassed by the formula 1, but not defined specifically.

Preferred herbicidal compositions comprise, as component (A), a compoundof the formula (I) where

R¹ is methyl;

R² is OR⁶;

R³ and R⁴ independently of one another are hydrogen, chlorine, fluorine,methyl, trifluoromethyl, cyano, nitro or SO₂R⁷;

R⁶ is hydrogen;

R⁷ is methyl or ethyl;

n is 0, 1 or 2;

m, a and b are in each case 2.

Also preferred are herbicidal compositions that comprise, as component(A), a compound of the formula (1), in which

R⁵ is O—(CH₂)_(a)—O—(CH₂)_(b)—OR⁷, C₃-C₈-cycloalkyloxy,C₃-C₈-cycloalkyl-C₁-C₄-alkyloxy or 2-tetrahydrofuranylmethoxy.

Furthermore preferred are herbicidal compositions that comprise, ascomponent (A), a compound of the formula (la) with the meanings statedhereinbelow:

No. R³ R⁴ R⁵ (A1) Cl SO₂CH₃

(A2) Cl SO₂CH₃

(A3) Cl SO₂CH₃

(A4) Cl SO₂CH₃

(A5) Cl SO₂CH₃ O(CH₂CH₂O)₂CH₂CH₃ (A6) CF₃ SO₂CH₂CH₃ O(CH₂CH₂O)₂CH₂CH₃(A7) Cl SO₂CH₂CH₃

(A8) Cl SO₂CH₂CH₃

(A9) CF₃ SO₂CH₂CH₃ O(CH₂CH₂O)₂CH₃ (A10) CH₃ SO₂CH₃ O(CH₂CH₂O)₂CH₃ (A11)Cl SO₂CH₃ O(CH₂CH₂O)₂CH₃ (A12) CH₃ SO₂CH₃ O(CH₂CH₂O)₂CH₂CH₃

Preferred as component (B) are the herbicides benzobicyclon, benzofenap,bifenox, cafenstrole, cinmethylin, dimethametryn, dithiopyr,etobenzamide, fentrazamide, indanofan, oxadiazon, piperophos,pyributicarb, pyriftalide, pyriminobac-methyl and quinoclamine.

Especially preferred in this context are the herbicides cafenstrole,dithiopyr, etobenzamide, fentrazamide, indanofan, oxadiazon,pyributicarb, pyriftalide, pyriminobac-methyl and quinoclamine.

The active ingredients whose common names have been stated hereinaboveare known, for example, from “The Pesticide Manual”, 12th Edition, 2000,British Crop Protection Council, or can be seen from the table whichfollows:

Common name or code No. Structure Pyriftalide (NOJ-100)

Herbicidal compositions which are of particular interest in this contextare those with a synergistically active content of one or more of thefollowing combinations of two compounds (A)+(B):

(A1)+(B1.1), (A1)+(B1.2), (A1)+(B2.1), (A1)+(B3.1), (A1)+(B4.1),(A1)+(B4.2), (A1)+(B5.1), (A1)+(B5.2), (A1)+(B5.3), (A1)+(B5.4),(A1)+(B5.5), (A1)+(B6.1), (A1)+(B6.2), (A1)+(B6.3), (A1)+(B7.1),(A1)+(B8.1), (A1)+(B9.1), (A1)+(B10.1), (A1)+(B11.1), (A1)+(B12.1),(A1)+(B13.1), (A1)+(B14.1),

(A2)+(B1.1), (A2)+(B1.2), (A2)+(B2.1), (A2)+(B3.1), (A2)+(B4.1),(A2)+(B4.2), (A2)+(B5.1), (A2)+(B5.2), (A2)+(B5.3), (A2)+(B5.4),(A2)+(B5.5), (A2)+(B6.1), (A2)+(B6.2), (A2)+(B6.3), (A2)+(B7.1),(A2)+(B8.1), (A2)+(B9.1), (A2)+(B10.1), (A2)+(B11.1), (A2)+(B12.1),(A2)+(B13.1), (A2)+(B14.1),

(A3)+(B1.1), (A3)+(B1.2), (A3)+(B2.1), (A3)+(B3.1), (A3)+(B4.1),(A3)+(B4.2), (A3)+(B5.1), (A3)+(B5.2), (A3)+(B5.3), (A3)+(B5.4),(A3)+(B5.5), (A3)+(B6.1), (A3)+(B6.2), (A3)+(B6.3), (A3)+(B7.1),(A3)+(B8.1), (A3)+(B9.1), (A3)+(B10.1), (A3)+(B11.1), (A3)+(B12.1),(A3)+(B13.1), (A3)+(B14.1),

(A4)+(B1.1), (A4)+(B1.2), (A4)+(B2.1), (A4)+(B3.1), (A4)+(B4.1),(A4)+(B4.2), (A4)+(B5.1), (A4)+(B5.2), (A4)+(B5.3), (A4)+(B5.4),(A4)+(B5.5), (A4)+(B6.1), (A4)+(B6.2), (A4)+(B6.3), (A4)+(B7.1),(A4)+(B8.1), (A4)+(B9.1), (A4)+(B10.1), (A4)+(B11.1), (A4)+(B12.1),(A4)+(B13.1), (A4)+(B14.1),

(A5)+(B1.1), (A5)+(B1.2), (A5)+(B2.1), (A5)+(B3.1), (A5)+(B4.1),(A5)+(B4.2), (A5)+(B5.1), (A5)+(B5.2), (A5)+(B5.3), (A5)+(B5.4),(A5)+(B5.5), (A5)+(B6.1), (A5)+(B6.2), (A5)+(B6.3), (A5)+(B7.1),(A5)+(B8.1), (A5)+(B9.1), (A5)+(B10.1), (A5)+(B11.1), (A5)+(B12.1),(A5)+(B13.1), (A5)+(B14.1),

(A6)+(B1.1), (A6)+(B1.2), (A6)+(B2.1), (A6)+(B3.1), (A6)+(B4.1),(A6)+(B4.2), (A6)+(B5.1), (A6)+(B5.2), (A6)+(B5.3), (A6)+(B5.4),(A6)+(B5.5), (A6)+(B6.1), (A6)+(B6.2), (A6)+(B6.3), (A6)+(B7.1),(A6)+(B8.1), (A6)+(B9.1), (A6)+(B10.1), (A6)+(B11.1), (A6)+(B12.1),(A6)+(B13.1), (A6)+(B14.1),

(A7)+(B1.1), (A7)+(B1.2), (A7)+(B2.1), (A7)+(B3.1), (A7)+(B4.1),(A7)+(B4.2), (A7)+(B5.1), (A7)+(B5.2), (A7)+(B5.3), (A7)+(B5.4),(A7)+(B5.5), (A7)+(B6.1), (A7)+(B6.2), (A7)+(B6.3), (A7)+(B7.1),(A7)+(B8.1), (A7)+(B9.1), (A7)+(B10.1), (A7)+(B11.1), (A7)+(B12.1),(A7)+(B13.1), (A7)+(B14.1),

(A8)+(B1.1), (A8)+(B1.2), (A8)+(B2.1), (A8)+(B3.1), (A8)+(B4.1),(A8)+(B4.2), (A8)+(B5.1), (A8)+(B5.2), (A8)+(B5.3), (A8)+(B5.4),(A8)+(B5.5), (A8)+(B6.1), (A8)+(B6.2), (A8)+(B6.3), (A8)+(B7.1),(A8)+(B8.1), (A8)+(B9.1), (A8)+(B10.1), (A8)+(B11.1), (A8)+(B12.1),(A8)+(B13.1), (A8)+(B14.1),

(A9)+(B1.1), (A9)+(B1.2), (A9)+(B2.1), (A9)+(B3.1), (A9)+(B4.1),(A9)+(B4.2), (A9)+(B5.1), (A9)+(B5.2), (A9)+(B5.3), (A9)+(B5.4),(A9)+(B5.5), (A9)+(B6.1), (A9)+(B6.2), (A9)+(B6.3), (A9)+(B7.1),(A9)+(B8.1), (A9)+(B9.1), (A9)+(B10.1), (A9)+(B11.1), (A9)+(B12.1),(A9)+(B13.1), (A9)+(B14.1),

(A10)+(B1.1), (A10)+(B1.2), (A10)+(B2.1), (A10)+(B3.1), (A10)+(B4.1),(A10)+(B4.2), (A10)+(B5.1), (A10)+(B5.2), (A10)+(B5.3), (A1)+(B5.4),(A1)+(B5.5), (A10)+(B6.1), (A10)+(B6.2), (A10)+(B6.3), (A10)+(B7.1),(A1)+(B8.1), (A1)+(B9.1), (A10)+(B10.1), (A10)+(B11.1), (A10)+(B12.1),(A10)+(B13.1), (A10)+(B14.1),

(A11)+(B1.1), (A11)+(B1.2), (A11)+(B2.1), (A11)+(B3.1), (A11)+(B4.1),(A11)+(B4.2), (A11)+(B5.1), (A11)+(B5.2), (A11)+(B5.3), (A1)+(B5.4),(A1)+(B5.5), (A11)+(B6.1), (A11)+(B6.2), (A11)+(B6.3), (A11)+(B7.1),(A1)+(B8.1), (A1)+(B9.1), (A11)+(B10.1), (A11)+(B11.1), (A11)+(B12.1),(A11)+(B13.1), (A11)+(B14.1),

(A12)+(B1.1), (A12)+(B1.2), (A12)+(B2.1), (A12)+(B3.1), (A12)+(B4.1),(A12)+(B4.2), (A12)+(B5.1), (A12)+(B5.2), (A12)+(B5.3), (A1)+(B5.4),(A1)+(B5.5), (A12)+(B6.1), (A12)+(B6.2), (A12)+(B6.3), (A12)+(B7.1),(A1)+(B8.1), (A1)+(B9.1), (A12)+(B10.1), (A12)+(B11.1), (A12)+(B12.1),(A12)+(B13.1), (A12)+(B14.1),

With the combinations according to the invention, application rates inthe range of from 1 to 2 000 g, preferably 10 to 500 g, of activeingredient component (A) and from 1 to 2 000 g, preferably 1 to 500 g,of component (B) are generally required per hectare (ai/ha).

The weight ratios of components (A) to (B) to be employed can be variedwithin wide ranges. The quantitative ratio is preferably in the range offrom 1:50 to 500:1, in particular in the range of from 1:20 to 50:1.Optimal weight ratios can depend on the field of application inquestion, the weed spectrum and the active ingredient combinationemployed and can be determined in preliminary experiments.

The compositions according to the invention are outstandingly suitablefor the selective control of harmful plants in rice crops.

The compositions according to the invention can be employed in all thosemodes of application which are conventional for rice herbicides. Theyare especially advantageously employed in the form of spray applicationand submerged application. In what is known as submerged application,the paddy water already has a depth of up to 30 mm above the soil at thepoint in time of application. The compositions according to theinvention are added to the paddy water directly, for example in the formof granules. Worldwide, spray application is employed predominantly inseeded rice and what is known as submerged application predominantly intransplanted rice.

The compositions according to the invention act on a broad weedspectrum. For example, they are suitable for controlling annual andperennial harmful plants such as, for example, from the speciesAbutilon, Alopecurus, Avena, Chenopodium, Cynodon, Cyperus, Digitaria,Echinochloa, Elymus, Galium, Ipomoea, Lamium, Matricaria, Scirpus,Setaria, Sorghum, Veronica, Viola and Xanthium, in particularEchinochloa spp., Leptochloa spp., Scirpus spp., Cyperus spp.,Sagittaria spp., Monochoria spp., Lindernia spp., Eleocharis spp. andSesbania spp.

The herbicidal compositions according to the invention are alsodistinguished by a reduced effective dosage of components (A) and (B)used in the combinations in comparison with individual dosage, so that areduction in the required active ingredient rates is made possible.

The invention also relates to a method of controlling undesiredvegetation, which comprises applying one or more herbicides (A) togetherwith one or more herbicides (B) to the harmful plants, plant partsthereof, or the area under cultivation.

When type (A) and (B) herbicides are applied jointly, superadditive(=synergistic) effects are observed. The action of the combinationsexceeds the expected total of the actions of the individual herbicidesemployed and the action of each individual herbicide (A) ad (B). Thesynergistic effects allow a reduction in application rate, the controlof a broader spectrum of broad-leaved and grass weeds, a more rapidonset of the herbicidal action, a prolonged duration of action, a bettercontrol of the harmful plants with only one or few applications, and anextension of the application period which is possible. These propertiesare required in weed control practice to keep agricultural crops freefrom undesired competing plants, thus safeguarding and/or increasing theyields in terms of quality and quantity. The technical standard ismarkedly exceeded by these new combinations with regard to theproperties described.

The active ingredient combinations according to the invention can bothbe present as mixed formulations of components (A) and (B), ifappropriate together with further customary formulation auxiliaries,which are then applied in the customary manner in the form of a dilutionwith water, or can be prepared as what are known as tank mixes, byjointly diluting the components, all or some of which are formulatedseparately, with water.

Components (A) and (B) can be formulated in various ways, depending onthe prevailing biological and/or chemico-physical parameters. Thefollowing are suitable as examples of formulations which are generallypossible: wettable powders (WP), emulsifiable concentrates (EC), aqueoussolutions (SL), emulsions (EW) such as oil-in-water and water-in-oilemulsions, sprayable solutions or emulsions, oil- or water-baseddispersions, suspoemulsions, dusts (DP), seed-dressing products,granules for soil application or spreading, water-dispersible granules(WG), ULV formulations, microcapsules or waxes.

The individual types of formulation are known in principle and aredescribed, for example, in: Winnacker-Küchler, “Chemische Technologie”[Chemical Engineering], Volume 7, C. Hauser Verlag Munich, 4th Ed. 1986;van Valkenburg, “Pesticides Formulations”, Marcel Dekker N.Y., 1973; K.Martens, “Spray Drying Handbook”, 3rd Ed. 1979, G. Goodwin Ltd. London.The formulation auxiliaries required, such as inert materials,surfactants, solvents and further additives, are likewise known and aredescribed, for example, in: Watkins, “Handbook of Insecticide DustDiluents and Carriers”, 2nd Ed., Darland Books, Caldwell N.J.; H.v.Olphen, “Introduction to Clay Colloid Chemistry”; 2nd Ed., J. Wiley &Sons, N.Y. Marsden, “Solvents Guide”, 2nd Ed., Interscience, N.Y. 1950;McCutcheon'ss, “Detergents and Emulsifiers Annual”, MC Publ. Corp.,Ridegewood N.J.; Sisley and Wood, “Encyclopedia of Surface ActiveAgents”, Chem. Publ. Co. Inc., N.Y. 1964; Schönfeldt,“Grenzflächenaktive Äthylenoxidaddukte” [Surface-active ethylene oxideadducts], Wiss. Verlagsgesellschaft, Stuttgart 1976, Winnacker-Küchler,“Chemische Technologie”, Volume 7, C. HauserVerlag Munich, 4th Ed. 1986.

Based on these formulations, combinations with other pesticidally activesubstances, such as other herbicides, fungicides or insecticides, andwith safeners, fertilizers and/or growth regulators, may also beprepared, for example in the form of a readymix or a tank mix.

Wettable powders are products which are uniformly dispersible in waterand which, besides the active ingredient, also comprise ionic ornonionic surfactants (wetters, dispersants), for example polyoxethylatedalkylphenols, polyethoxylated fatty alcohols or fatty amines,alkanesulfonates, alkylbenzenesulfonates, sodium lignosulfonates, sodium2,2′-dinaphthylmethane-6,6′-disulfonate, sodiumdibutylnaphthalinesulfonate, or else sodium oleoylmethyltauride, inaddition to a diluent or inert material.

Emulsifiable concentrates are prepared by dissolving the activeingredient in an organic solvent, for example butanol, cyclohexanone,dimethylformamide, xylene or else higher-boiling aromatics orhydrocarbons with addition of one or more ionic or nonionic surfactants(emulsifiers). Examples of emulsifiers which may be used are: calciumsalts of alkylarylsulfonic acids, such as calciumdodecylbenzenesulfonate, or nonionic emulsifiers such as fatty acidpolyglycol esters, alkylaryl polyglycol ethers, fatty alcohol polyglycolethers, propylene oxide/ethylene oxide condensates, alkyl polyethers,sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid estersor polyoxethylene sorbitol esters.

Dusts are obtained by grinding the active ingredient with finely dividedsolid materials, for example talc, natural clays such as kaolin,bentonite and pyrophyllite, or diatomaceous earth.

Granules can be prepared either by spraying the active ingredient ontoadsorptive granulated inert material or by applying active ingredientconcentrates to the surface of carriers such as sand, kaolinites orgranulated inert material with the aid of adhesives, for examplepolyvinyl alcohol, sodium polyacrylate or else mineral oils. Suitableactive ingredients may also be granulated in the manner conventionallyused for fertilizer granules, if desired in a mixture with fertilizers.As a rule, water-dispersible granules are prepared by processes such asspray drying, fluidized-bed granulation, disk granulation, mixing withhigh-speed mixers, and extrusion without solid inert material.

The agrochemical formulations comprise, as a rule, from 0.1 to 99percent by weight, in particular from 0.2 to 95% by weight, of activeingredient types (A) and (B), the following concentrations beingcustomary, depending on the type of formulation: the active ingredientconcentration in wettable powders is, for example, from approximately 10to 95% by weight, the remainder to 100% by weight being composed ofcustomary formulation constituents. In the case of emulsifiableconcentrates, the active ingredient concentration may amount to, forexample, 5 to 80% by weight. Formulations in the form of dust usuallycomprise from 5 to 20% by weight of active ingredient, and sprayablesolutions comprise approximately from 0.2 to 25% by weight of activeingredient. In the case of granules, such as dispersible granules, theactive ingredient content depends partly on whether the active compoundis present in liquid or solid form and on which granulation auxiliariesand fillers are being used. As a rule, the active ingredient contentamounts to between 10 and 90% by weight in the case of thewater-dispersible granules. In addition, the abovementioned activeingredient formulations comprise, if appropriate, the adhesives,wetters, dispersants, emulsifiers, preservatives, antifreeze agents,solvents, fillers, colorants, carriers, antifoams, evaporationinhibitors, pH regulators or viscosity regulators which are customary ineach case.

For use, the formulations, which are present in commercially availableform, are, if appropriate, diluted in the customary manner, for exampleusing water in the case of wettable powders, emulsifiable concentrates,dispersions and water-dispersible granules. Preparations in the form ofdusts, soil granules, granules for spreading, and sprayable solutions,are usually not diluted any further with other inert substances prior touse.

The active ingredients can be applied to the plants, plant parts, plantseeds or the area under cultivation (arable soil), preferably to thegreen plants and plant parts and, if appropriate, additionally to thearable soil.

One possible use is the joint application of active ingredients in theform of tank mixes, the optimally formulated concentrated formulationsof the individual active ingredients jointly being mixed with water inthe tank and the spray mixture obtained being applied.

A herbicidal coformulation of the combination according to the inventionof components (A) and (B) has the advantage of greater ease on use sincethe amounts of the components are already presented in the correctproportion. Moreover, the auxiliaries in the formulation can be adjustedto match each other optimally, while a tank mix of differentformulations may result in undesired combinations of auxiliaries.

A. FORMULATION EXAMPLES

a) A dust (WP) is obtained by mixing 10 parts by weight of an activeingredient/active ingredient mixture and 90 parts by weight of talc asinert substance and comminuting the mixture in a hammer mill.

b) A wettable powder (WG) which is readily dispersible in water isobtained by mixing 25 parts by weight of an active ingredient/activeingredient mixture, 64 parts by weight of kaolin-containing quartz asinert material, 10 parts by weight of potassium lignosulfonate and 1part by weight of sodium oleoylmethyltauride as wetter and dispersantand grinding the mixture in a pinned-disk mill.

c) A dispersion concentrate which is readily dispersible in water isobtained by mixing 20 parts by weight of an active ingredient/activeingredient mixture with 6 parts by weight of alkylphenyl polyglycolether (Triton X 207), 3 parts by weight of isotridecanol polyglycolether (8 EO) and 71 parts by weight of paraffinic mineral oil (boilingrange, for example, approx. 255 to 277° C.) and grinding the mixture ina friction bowl mill to a fineness of under 5 microns.

d) An emulsifiable concentrate (EC) is obtained from 15 parts by weightof an active ingredient/active ingredient mixture, 75 parts by weight ofcyclohexanone as solvent and 10 parts by weight of oxethylatednonylphenol as emulsifier.

e) Water-dispersible granules are obtained by mixing

75 parts by weight of an active ingredient/active ingredient mixture,

10 parts by weight of calcium lignosulfonate,

5 parts by weight of sodium lauryl sulfate,

3 parts by weight of polyvinyl alcohol and

7 parts by weight of kaolin,

grinding the mixture in a pinned-disk mill and granulating the powder ina fluidized bed by spraying on water as granulating fluid.

f) Water-dispersible granules are also obtained by homogenizing andpre-comminuting

25 parts by weight of an active ingredient/active ingredient mixture,

5 parts by weight of sodium 2,2′-dinaphthylmethane-6,6′-disulfonate,

2 parts by weight of sodium oleoylmethyltauride,

1 part by weight of polyvinyl alcohol,

17 parts by weight of calcium carbonate and

50 parts by weight of water

in a colloid mill, subsequently grinding the mixture in a bead mill, andatomizing and drying the suspension thus obtained in a spray tower bymeans of a single-substance nozzle.

B. BIOLOGICAL EXAMPLES

1. Pre-emergence herbicidal action

Seeds or root segments of monocotyledonous and dicotyledonous harmfulplants are placed in sandy loam in pots and covered with soil. In thecase of spray application, the compositions formulated as concentratedaqueous solutions, wettable powders or emulsion concentrates, are thenapplied to the surface of the covering soil as aqueous solution,suspension or emulsion, respectively, at an application rate of 600 to800 l of water per ha (converted) in a variety of dosages. Immediatelyto a few days after the application, the test containers are floodedwith water up to a depth of 30 mm above the soil surface. In the case ofsubmerged application, in contrast, the soil in the closed testcontainer is already covered with paddy water up to a depth of 30 mm atthe time of application. Here, the formulated active ingredients areadded directly to the paddy water, for example in the form of granules.After the treatment, the pots are placed in a greenhouse and kept undergood growth conditions for the weeds. Visual scoring of the plant damageor the adverse effect on the emergence is carried out after the testplants have emerged after an experimental period of 3 to 4 weeks incomparison with untreated controls. As demonstrated by the test results,the compositions according to the invention have an outstandingpre-emergence herbicidal action against a broad spectrum of grass weedsand broad-leaved weeds. Frequently, effects of the combinationsaccording to the invention are observed which exceed the formal total ofthe effects when the herbicides are applied individually. When usingsuitable low dosages, the values observed in the experiments show aneffect of the combinations which exceed the expected values calculatedusing Colby's formula.

Scoring and assessing the synergistic herbicidal effects:

The herbicidal efficacy of the active ingredients or active ingredientmixtures was scored visually by comparing the treated variants withuntreated control variants. The damage and development of all aerialplant parts was recorded. Scoring was done on a percentage scale (100%action=all plants dead; 50% action=50% of the plants and green plantparts dead; 0% action=no discernible action=like untreated controlplot).

2. Post-emergence herbicidal action

Seeds or root segments of monocotyledonous and dicotyledonous weeds areplaced in sandy loam in pots, covered with soil and grown in thegreenhouse under good growth conditions (temperature, atmospherichumidity, water supply). Approximately three weeks after planting, theexperimental plants are treated with the compositions according to theinvention. In the case of spray application, the compositions accordingto the invention, which are formulated as wettable powders or emulsionconcentrates, are sprayed onto the green plant parts in various dosageswith an application rate of 600 to 800 l of water per ha (converted).Immediately to a few days after the application, the test containers areflooded with water up to a depth of 30 mm above the soil surface. In thecase of submerged application, in contrast, the soil in the closed testcontainer is already covered with paddy water up to a depth of 30 mm atthe time of application. Here, the formulated active ingredients areadded directly to the paddy water. After the experimental plants haveremained in the greenhouse under optimal growth conditions for a further3 to 4 weeks, the effect of the preparations is scored visually incomparison with untreated controls. The compositions according to theinvention also have an outstanding herbicidal action against a broadspectrum of economically important grass weeds and broad-leaved weedswhen applied post-emergence. Frequently, effects of the combinationsaccording to the invention are observed which exceed the formal total ofthe effects when the herbicides are applied individually. When usingsuitable low dosages, the values observed in the experiments show aneffect of the combinations which exceed the expected values calculatedusing Colby's formula.

3. Herbicidal action and crop plant tolerance (field experiments)

Crop plants were grown in the open on plots under natural fieldconditions, seeds or root segments of typical harmful plants having beenplanted and the natural weed flora being exploited. The treatment withthe compositions according to the invention was carried out as sprayapplication or submerged application after the harmful plants and thecrop plants had emerged, as a rule in the 2- to 4-leaf stage; in somecases (as stated), individual active ingredients or active ingredientcombinations were applied pre-emergence or as sequential treatment,partly pre-emergence and/or post-emergence. After the application, forexample 2, 4, 6 and 8 weeks after the application, the effect of thepreparations is scored visually in comparison with untreated controls(for scoring, see Example 1). The compositions according to theinvention also have a synergistic herbicidal activity against a broadspectrum of economically important grass weeds and broad-leaved weeds infield experiments. The comparison demonstrated that the combinationsaccording to the invention have in most cases a more potent, in somecases a considerably more potent, herbicidal action than the total ofthe actions of the individual herbicides and therefore suggestssynergism. Moreover, the effects exceeded the expected values calculatedusing Colby's formula during important parts of this scoring period, andtherefore likewise suggest synergism. The crop plants, in contrast, wereleft unharmed or virtually unharmed as the consequence of treatment withthe herbicidal compositions.

When applying the combinations according to the invention, herbicidaleffects are frequently observed on a harmful plant species which exceedthe formal total of the effects of the herbicides present when these areapplied by themselves. Alternatively, it is observed in some cases thata lower application rate is required for the herbicide combination inorder to achieve the same effect on a harmful plant species incomparison with the individual products. Such increases in action orefficacy, or reduced application rates, strongly suggest a synergisticeffect. When the data observed already exceed the formal total of thedata in the experiments with individual applications, they likewiseexceed the expected value calculated by Colby's formula hereinbelow,which is likewise regarded as suggesting synergism (cf. S. R. Colby; inWeeds 15 (1967) pp. 20 to 22): $E = {A + B - \frac{A \times B}{100}}$

In this formula:

A, B=action of component A or B in percent at a dosage of a and b gramsof ai/ha, respectively, and

E=expected value in % at a dosage of a+b grams of ai/ha.

The data observed in the abovementioned experimental examples exceed theexpected values calculated using Colby's formula.

Examples B.I to B.XVII have been conducted according to method B.2(post-emergence herbicidal action) as mentioned above, wherein sprayapplication has been applied in case of examples B.I to B.V. Submergedapplication has been applied in case of examples B.VI bis B.XVII.

The abbreviations denote:

CHEAL Chenopodium album CYPSE Cyperus serotinus ECHCG Echinochloa crusgalli SAGPY Sagittaria pygmaea SCPJU Scirpus juncoides SEBEX Sesbaniaexaltata

EXAMPLE B.I

CHEAL Dosage value E Compound [g ai/ha] found (according to Colby) A1 1025% B6.2 10 10% A1 + B6.2 10 + 10 75% 33%

EXAMPLE B.II

ECHCG SEBEX value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 20 15% 15% B1.1 100 50% 45%A1 + B1.1 20 + 100 73% 58% 85% 53%

EXAMPLE B.III

ECHCG SEBEX value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 20 35% 15% B8.1 100 25% 50%A1 + B8.1 20 + 100 55% 51% 98% 58%

EXAMPLE B.IV

ECHCG CYPES value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 20 15% 15% B13.1 20 30%  0%A1 + B13.1 20 + 20 70% 41% 30% 15%

EXAMPLE B.V

ECHCG SEBEX value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 20 15% 15% B14.1 500  0%  0%A1 + B14.1 20 + 100 45% 25% 30% 15%

EXAMPLE B.VI

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 37.5 30%  70% B2.1 75 30%  0%A1 + B2.1 37.5 + 75 80% 51% 100% 70%

EXAMPLE B.VII

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5  70% B3.1 300  0%75  0% A1 + B3.1   75 + 300 90% 50% 37.5 + 75  100% 70%

EXAMPLE B.VIII

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5 70% B5.1 75  0%150  0% A1 + B5.1   75 + 75  80% 50% 37.5 + 150 90% 70%

EXAMPLE B.IX

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5  70% B7.1 15  0%30  0% A1 + B7.1   75 + 15 80% 50% 37.5 + 30 100% 70%

EXAMPLE B.X

SAGPY CYPSE value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 37.5  70% 75 40% B5.2 375  0%750  0% A1 + B5.2 37.5 + 75  100% 70%   75 + 750 80% 40%

EXAMPLE B.XI

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5  70% B5.3 15  0% 0% A1 + B5.3   75 + 15 80% 50% 37.5 + 15 100% 70%

EXAMPLE B.XII

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5 70% B9.1 375  0%187  0% A1 + B9.1   75 + 375 60% 50% 37.5 + 187 90% 70%

EXAMPLE B.XIII

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 18 20% 37.5  70% B5.4 75  0%37.5  0% A1 + B5.4 18 + 75 50% 20% 37.5 + 37.5 100% 70%

EXAMPLE B.XIV

ECHOR SCPJU value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75  60% 37.5 30% B10.1 18.75 50% 37.5 20% A1 + B10.1   75 + 18.75 100% 80% 37.5 + 37.5  80% 44%

EXAMPLE B.XV

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 18 20% 37.5 70% B4.2 22 10%175  0% A1 + B4.2 18 + 22 50% 28% 37.5 + 175 90% 70% 

EXAMPLE B.XVI

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 37.5  70% B12.1 100  0%50  0% A1 + B12.1   75 + 100  70% 50% 37.5 + 50   100% 70%

EXAMPLE B.VXII

SCPJU SAGPY value E value E Dosage (according (according Compound [gai/ha] found to Colby) found to Colby) A1 75 50% 18 50% B6.3 7.5  0%  0%A1 + B6.3 75 + 7.5 80% 50% 18 + 7.5 80% 50%

We claim:
 1. A herbicidal composition comprising a synergisticallyeffective amount of A) at least one compound of the formula (I) andagriculturally customary salts thereof

 where R¹ is C₁-C₄-alkyl; R² is OR⁶, SO_(m)R⁷, cyanato, cyano,thiocyanato or halogen; R³ and R⁴ independently of one another arehydrogen, halogen, C₁-C₄-alkyl, halogen-C₁-C₄-alkyl, cyano, nitro orSO_(m)R⁷; R⁵ is O—(CH₂)_(a)—O—(CH₂)_(b)—OR⁷, C₃-C₈-cycloalkyloxy,C₃-C₈-cycloalkyl-C₁-C₄-alkyloxy, 2-tetrahydrofuranylmethoxy,3-tetrahydrofuranylmethoxy, 2-tetrahydro-2H-pyranylmethoxy,2-tetrahydrothienylmethoxy, 2-furanylmethoxy or 2-thienylmethoxy; R⁶ ishydrogen, C₁-C₄-alkyl or halogen-C₁-C₄-alkyl; R⁷ is C₁-C₄-alkyl,C₂-C₄-alkenyl, C₂-C₄-alkynyl, halogen-C₁-C₄-alkyl, halogen-C₂-C₄-alkenylor halogen-C₂-C₄-alkynyl; n is 0, 1, 2, 3, 4, 5 or 6; m is 0, 1 or 2; ais 2, 3 or 4; b is 2, 3 or 4; and B) at least one compound from thegroup consisting of the herbicides 2,4-D, benzobicyclon, benzofenap,bifenox, cafenstrole, chlorimuron-ethyl, cinmethylin, daimuron,dimethametryn, dithiopyr, etobenzamide, fentrazamide, indanofan, MCPA,oxadiazon, piperophos, pyrazosulfuron-ethyl, pyributicarb, pyriftalide(NOJ-100), pyriminobac-methyl, profoxydim and quinoclamine, thesecompositions comprising the compounds of the formula (I) or saltsthereof and the compounds of the group B) in a weight ratio of 1:2000 to2000:1.
 2. A herbicidal composition as claimed in claim 1, whichcomprises, as component (A), a compound of the formula (I) where R¹ ismethyl; R² is OR⁶; R³ and R⁴ independently of one another are hydrogen,chlorine, fluorine, methyl, trifluoromethyl, cyano, nitro or SO₂R⁷; R⁶is hydrogen; R⁷ is methyl or ethyl; n is 0, 1 or 2; m, a and b are ineach case
 2. 3. A herbicidal composition as claimed in claim 1, whichcomprises, as component (A), a compound of the formula I where R⁵ isO—(CH₂)_(a)—O—(CH₂)_(b)—OR⁷, C₃-C₈-cycloalkyloxy,C₃-C₈-cycloalkyl-C₁-C₈cycloalkyl-C₁-C₄alkyloxy or2-tetrahydrofuranylmethoxy.
 4. A herbicidal composition as claimed inclaim 1, which comprises, as component (B), a herbicide from the groupconsisting of benzobicyclon, benzofenap, bifenox, cafenstrol,cinmethylin, dimethametryn, dithiopyr, etobenzamide, fentrazaminde,idanofan, oxadiazon, piperophos, pyributicarb, pyriftalide,pyriminobac-methyl and quinoclamine.
 5. A herbicidal composition asclaimed in claim 4, which comprises at least one herbicide from thegroup consisting of cafenstrole, dithiopyr, etobenzamide, fentrazamide,idanofan, oxadiazon, pyributicarb, pyriftalide, pyriminobac-methyl andquinoclamine.
 6. A herbicidal composition as claimed in claim 1, whereinthe weight ratio A:B of the combined herbicides (A) and (B) is in therange of 1:20 to 20:1.
 7. A herbicidal composition as claimed in claim1, which comprises 0.1-99% by weight of herbicides (A) and (B) and 99 to0.1% by weight of formulation auxiliaries conventionally used in cropprotection.
 8. A method of controlling undesired vegetation, whichcomprises applying one or more herbicides (A) together with one or moreherbicides (B) to the harmful plants, plant parts thereof or the areaunder cultivation, the combination of the herbicides (A) and (B) beingas defined in claim 1.